ST_Geometry::ST_AsSVGAggr(geometry-column[ ORDER BY order-by-expression [ ASC | DESC ], ... ] [, format])

The ST_AsSVGAggr method returns a complete or partial SVG document that can be used to graphically display the union of a group of geometries using an SVG viewer. Most major web browsers with the exception of Microsoft Internet Explorer include built-in SVG viewers.

A number of different options are supported and the desired format is selected using the optional format parameter. If the format parameter is not specified, the default is 'SVG'.

The format string defines an output format and parameters to the format. The format string has one of the following formats:

format-name

format-name(parameter1=value1;parameter2=value2;...)

parameter1=value1;parameter2=value2;...

The first format specifies the format name and no parameters. All format parameters use their default values. The second format specifies the format name and a list of named parameter values. Parameters that are not supplied use their default values. The last format specifies only parameter values, and the format name defaults to 'SVG'.

The following format names may be used:

The following format parameters can be specified:

The ORDER BY clause can be specified to control how overlapping geometries are displayed, with geometries displayed in order from back to front. If not specified, the geometries are displayed in an order that depends on the execution plan selected by the query optimizer, and this may vary between executions.

• ST_AsSVG method for type ST_Geometry

The following returns a complete SVG document with polygons filled with random colors.

SELECT ST_Geometry::ST_AsSVGAggr( Shape ) FROM SpatialShapes

The following returns a complete SVG document from SVG path data with relative coordinates limited to 5 digits after the decimal place.

SELECT '<?xml version="1.0" standalone="no"?>
	<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
	"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
	<svg viewBox="-10 -10 20 12" xmlns="http://www.w3.org/2000/svg" 
	    version="1.1">
	    <path fill="lightblue" stroke="black" stroke-width="0.1%" d="' ||
	      ST_Geometry::ST_AsSVGAggr( Shape, 'PathDataOnly=Yes' ) ||
       '"/></svg>'
FROM SpatialShapes

The following statements create a web service that returns a complete SVG document that renders all geometries in the SpatialShapes table. If the database server is started with the -xs http option, you can use a browser that supports SVG to display the SVG. To do this, browse to the address http://localhost/demo/svg_shapes This works assuming that the browser and the database server are on the same computer, and that the database is named demo).

CREATE SERVICE svg_shapes TYPE 'RAW' USER DBA AUTHORIZATION OFF
AS CALL svg_shapes();

CREATE PROCEDURE svg_shapes()
    RESULT( svg LONG VARCHAR )
BEGIN
    CALL sa_set_http_header( 'Content-type', 'image/svg+xml');
    SELECT ST_Geometry::ST_AsSVGAggr( Shape ) FROM SpatialShapes;
END;